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From: Portland, OR
Region: Northwest
Topic: Herbs/Forbs
Title: Rubber (latex) in Balloon plant (Asclepias physocarpa)
Answered by: Nan Hampton
Asclepias physocarpa is a native of southeast Africa and our focus and expertise is on natives of North America so this plant is not really in our purview. However, we can answer your question. The majority, if not all, of the milkweeds—in particular, the members of the Genus Asclepias, including A. physocarpa—contain the sticky white latex sap that you see when you cut or break the leaves or stems. The latex, plus other chemical components such as cardenolides, are the plants defense against herbivores. There are insects that do thrive on the milkweeds (e.g, the monarch butterfly, Danaus plexippus) and have devised strategies to subvert the plants's defenses. You can read more about the plants defense strategies in: Angrawal, A. and M. Fishbein. 2006. Plant Defense Syndromes. Ecology 87(7) Supplement. S132-S149.
Standing cypress turning brown in San Antonio
June 12, 2011 - Last year I bought and planted a standing cypress. This year several plants came up. The tallest one was about 1 foot tall. After blooming the plant began to turn brown and die. My question: Is t...
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Mealy blue sage drooping from Canyon Lake TX
May 07, 2013 - Mealy Blue Sage @ 4 ft Tall -
Planted three Mealy Blue Sage last year and they topped out at 2 ft tall. This year they are 4 ft tall in early May, and many of the stems are growing near horizontal...
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Native plants for full sun in Gwinnett County, Georgia
June 23, 2007 - I'm writing to you from Gwinnett County Parks and Rec. at the Pinckneyville Community Center in Norcross, GA.
We are looking to plant our garden and are wondering if you have any suggestions for min...
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Comment on poisonous sweet pea plant from Kalama WA
October 29, 2011 - No question, comment only. I am aware of the story of Christopher McCandless (Call of the Wild)and the belief that he was poisoned by ingesting part of the sweet pea plant; however I am curious what ...
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Failure to bloom of Turk's cap in Midland TX
September 08, 2009 - My turk's cap won't make flowers. It has daily watering via irrigation system, and soft amended soil. The plant is beautiful and thriving, but no flowers. What should I do?
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